Voice over IP (VOIP) or IP Telephony is an enabling technology. The underlying technology enables businesses to experience similar efficiencies brought about by data networks and applications such as e-mail. Without a doubt, VOIP based solutions will change the way businesses communicate and design voice networks. The implications of VOIP based solutions for the enterprise will be significant. The technology enables the underlying protocol and infrastructure to socket into the existing data networks. The characteristic of VOIP is best described by such terms as accessibility, application intelligence, portability, user control, presence, ubiquity, and pervasive